JUCE is an open-source cross-platform C++ application framework
Your Hardcore Loop Machine.
Audio Editor
An Audio/MIDI multi-track sequencer
Global Software Defined Radio at Your Fingertips
Audio DSP FX and plug-ins, mostly for guitar (amp sim) and other FX
vinylsimtool: simulation of vinyl record playback
Faust is a programming language for realtime audio signal processing
OctoGRIS3 is a multichannel sound spatialization plugin
The ZirkOSC3 is a plug-in that controls the Zirkonium
Cross platform C++ library for developping audio plugin´s UI
VST Plugins and loop player mixer